Table 1.

Sample Size Required for 90% Power to Detect a Difference in Means or a Difference in Responder Rates

μ	x0	Responder Rates		Per Group Sample	Per Group Sample
		pX	pC	Size – Difference in Means	Size – Difference in Rates
0.2	0	54.0%	46.0%	526	827
0.2	1	18.4%	13.6%	526	1204
0.2	2	2.9%	1.8%	526	4053
0.5	0	59.9%	40.1%	84	133
0.5	1	22.7%	10.6%	84	197
0.5	2	4.0%	1.2%	84	689
1.0	0	69.1%	30.9%	21	34
1.0	1	30.9%	6.7%	21	53
1.0	2	6.7%	0.6%	21	200